Hello, managers!
Followups to my question on determining tape left continue to come in. From
what I'm seeing, there really is no way to get a definitive answer. However,
many thanks to everyone who has gotten me a few steps closer. Here's what I've
been told lately:
WHERE IS TAPEX?
tapex is /usr/field/tapex
it is in kit OSFEXER350
-courtesy Lucio Chiappetti <lucio_at_ifctr.mi.cnr.it>
WHY DOESN'T DD WORK?
The problem with using /dev/zero as a data source is that
many drive support compression. And data which is a long
string of zeros compresses very, very well. Try using the
density that will give you the highest capacity, but not
turn on com[Apression.
-courtesy alan_at_nabeth.cxo.dec.com
BigRedDog <ckrieger_at_latrade.com>
Winfried Huber <win_at_tukan.ffb.eunet.de>
WHAT ELSE CAN I TRY?
#tcopy /dev/nrmt0h
file 0: block size 10240: 34 records
file 0: eof after 34 records: 348160 bytes
eot
total length: 348160 bytes
This is somewhat helpful, but again, compression varies and I won't know how
much tape is remaining.
-courtesy P.Ramadurai <durai_at_rri.ernet.in>
HOW CAN I DO IT BY HAND?
-courtesy Lucio Chiappetti <lucio_at_ifctr.mi.cnr.it>
1) to keep track of how many files has been written to tape, and
how many blocks
2) knowing the specification for the tape density (bytes per inch),
for the inter-record gap, and for the tape mark (inter-file gap)
3) estimate the space used from (1) and (2) ; this can be only an
estimate because gaps may be longer
4) Knowing he specification for the tape length
5) subtract (30 from (4)
I used to do something like that (up to step 3 at least) on my 800 bpi and
1600 bpi half inch tapes on HP RTE, for which I had the specification, but
I've been unable to locate specs for more modern devices.
Received on Thu Sep 19 1996 - 20:33:20 NZST